Removable pressure-sensitive adhesive sheets are not used in final products and generally incinerated after they are used during processing, transportation and so on. Therefore, since there has been a concern about the depletion of fossil resources or the increase in carbon dioxide due to combustion of fossil resources, which is a cause of global warming, they are required to be produced using plant-derived alternative materials, which are so-called carbon neutral, so that measures can be taken against that.
Synthetic rubbers and acryl-based pressure-sensitive adhesives have been used as adhesive materials for the removable pressure-sensitive adhesive sheets (Patent Documents 1 and 2), and unfortunately, at present, no available plant-derived acryl-based pressure-sensitive adhesive has been found.